Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice.
Ultraviolet (UV) treatment has been proven effective for killing a variety of microorganisms in liquid foods and on the surfaces of solid foods. However, there is a growing concern of inadequate decontamination in coloured and turbid fluids containing UV-absorbing compounds. Thus, the main objective...
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my.upm.eprints.272912014-04-11T08:42:58Z http://psasir.upm.edu.my/id/eprint/27291/ Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. Sew, Chang Chew Mohd Ghazali, Hasanah Olga, Martin-Belloso Mohd Adzahan, Noranizan Ultraviolet (UV) treatment has been proven effective for killing a variety of microorganisms in liquid foods and on the surfaces of solid foods. However, there is a growing concern of inadequate decontamination in coloured and turbid fluids containing UV-absorbing compounds. Thus, the main objective of this work was to examine the microbiocidal effect of mid-thermal and UV treatments on L. innocuo reduction in pineapple juice. Pineapples were peeled and cubed prior to juice extraction. The extracted juice was clarified using pectinase Ultra SP-l and filtered before inoculation with surrogate L. Innoeuo. The inoculated juice was given 4 separate treatments: (i) mid-thermal heating at 55 ·C for 10 minutes, (iI) UV treatments at different dosages (1.7 - 11.1 mJ/cm'), (iii) mid-thermal heating followed by UV treatments at different dosage, and (iv) heat pasteurisation at 95 ·C for 1 minute. The control sample was untreated pineapple juice. Exposure to mid-thermal heating caused a 4.62 ±0.40 log reduction of L. Innocuo, while the highest decontamination level achieved within the various UV doses applied (without mid-thermal treatment) was 2.16 ± 0.10 log reduction at 11.06 mJ/cm'. Results showed that the mid-thermal treatment increased the absorption coefficient of pineapple juice from 16.7 cm-' to 27.8 cm-', which increases the lethality of UV treatment. When mid-thermal treated juices were further treated with UV, an inactivation of N7 log reduction was observed indicating a synergistic effect. Similar level of inactivation was observed for conventionally pasteurised juices. Thus, the combined treatments could be a possible solution for pasteurising juices in cases when UV treatment alone is not sufficient. 2012 Conference or Workshop Item NonPeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/27291/1/ID%2027291.pdf Sew, Chang Chew and Mohd Ghazali, Hasanah and Olga, Martin-Belloso and Mohd Adzahan, Noranizan (2012) Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. In: International Nonthermal Food Processing Workshop – FIESTA 2012, 16-17 Oct. 2012, Melbourne, Australia. . (Submitted) English |
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Ultraviolet (UV) treatment has been proven effective for killing a variety of microorganisms in liquid foods and on the surfaces of solid foods. However, there is a growing concern of inadequate decontamination in coloured and turbid fluids containing UV-absorbing compounds. Thus, the main objective of this work was to examine the microbiocidal effect of mid-thermal and UV treatments on L. innocuo reduction in pineapple juice. Pineapples were peeled and cubed prior to juice extraction. The extracted juice was clarified using pectinase Ultra SP-l and filtered before inoculation with surrogate L. Innoeuo. The inoculated juice was given 4 separate treatments: (i) mid-thermal heating at 55 ·C for 10 minutes, (iI) UV treatments at different dosages (1.7 - 11.1 mJ/cm'), (iii) mid-thermal heating followed by UV treatments at different dosage, and (iv) heat pasteurisation at 95 ·C for 1 minute. The control sample was untreated pineapple juice. Exposure to mid-thermal heating caused a 4.62 ±0.40 log reduction of L. Innocuo, while the highest decontamination level achieved within the various UV doses applied (without mid-thermal treatment) was 2.16 ± 0.10 log reduction at 11.06 mJ/cm'. Results showed that the mid-thermal treatment
increased the absorption coefficient of pineapple juice from 16.7 cm-' to 27.8 cm-', which increases the lethality of UV treatment. When mid-thermal treated juices were further treated with UV, an inactivation of N7 log reduction was observed indicating a synergistic effect. Similar level of inactivation was observed for conventionally pasteurised juices. Thus, the combined treatments could be a possible solution for pasteurising juices in cases when UV treatment alone is not sufficient. |
format |
Conference or Workshop Item |
author |
Sew, Chang Chew Mohd Ghazali, Hasanah Olga, Martin-Belloso Mohd Adzahan, Noranizan |
spellingShingle |
Sew, Chang Chew Mohd Ghazali, Hasanah Olga, Martin-Belloso Mohd Adzahan, Noranizan Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
author_facet |
Sew, Chang Chew Mohd Ghazali, Hasanah Olga, Martin-Belloso Mohd Adzahan, Noranizan |
author_sort |
Sew, Chang Chew |
title |
Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
title_short |
Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
title_full |
Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
title_fullStr |
Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
title_full_unstemmed |
Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
title_sort |
effects of mid-thermal and ultraviolet treatments on listeria innocua inactivation in pineapple juice. |
publishDate |
2012 |
url |
http://psasir.upm.edu.my/id/eprint/27291/1/ID%2027291.pdf http://psasir.upm.edu.my/id/eprint/27291/ |
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1643829141546467328 |
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13.211869 |